The Honeycomb Izak or Natal Izak (Holohalaelurus favus) is a catshark belonging to the family Scyliorhinidae. They can be found in the Western Indian Ocean, near South Africa. Since the mid-1970s, no specimens have been collected, even with recent biodiversity research cruises (2002 and 2003).
Family: Scyliorhinidae – Catsharks
Genus: Holohalaelurus
Species: favus
Phylum– Chordata
Class– Chondrichthyles
Common Name– Ground Sharks
Family– Scyliorhinidae
Common Name– Catsharks
Genus– Holohalaelurus
Species– favus
Status: IUCN Red List ENDANGERED
Average Size and Length: Mature males measure between 52-55 cm/1.7-1.8 feet and mature females measure between 38-44 cm/1.2-1.4 feet.
Average Weight: .66 pounds.
Current Rare Mythical Sightings: Two forms of H. regani were once recognized: the “Cape” or “typical” form and the “Natal” or “northeastern” form. The latter “northeastern” form was described as a separate species, H. favus, in 2006.
Teeth and Jaw: The buccal papillae in the mouth are large and prominent on upper and lower surfaces. There are no furrows at the corners. The upper and lower jaws contain on average 65 and 60 tooth rows. Each tooth is relatively large, with a narrow central cusp flanked by 1–2 smaller cusplets. There are relatively high tooth counts, 65 total upper teeth in the holotype, 66 in the paratype, the mean is 66.3. There are 70 total lower teeth in the holotype, 58 in paratype, and the mean is mean 60.3.
Head: The head is very short, wide, and flattened, with a blunt snout. The horizontally oval eyes are placed high on the head and have thick ridges beneath. They eyes are equipped with nictitating membranes and is followed by a spiracle. The nostrils are preceded by triangular flaps of skin that almost reach the mouth.
Denticles: There are dermal denticles on dorsal midline that are greatly enlarged from snout to second dorsal origin. There are dermal denticles on pectoral fin dorsal surface that are greatly enlarged in adults.
Tail: The caudal peduncle is long and thin, particularly in younger sharks. The caudal fin makes up one-fourth to one-fifth of the total length and has a weak lower lobe and a ventral notch near the tip of the upper lobe.
Demographic, Distribution, Habitat, Environment and Range: The Honeycomb Izak or Natal Izak is found in the Western Indian Ocean, near South Africa in KwaZulu-Natal and Mozambique. They can be found between 656- 2,428 feet. Juveniles occur in deeper water than adults do. They are pelagic-oceanic.
Diet: They eat small bony fish, crustaceans, cephalopods, polychaetes, hydrozoans.
Aesthetic Identification: They are covered in irregularly shaped spots and reticulations on a brown background, resembling a honeycomb pattern; white spots rarely present, if present, are inconspicuous. They are yellowish to yellowish brown and white ventrally. The body of the Honeycomb Izak is firm and stout, tapering dramatically towards the tail. The pectoral fins are long and broad. The first dorsal fin originates over the rear of the pelvic fin bases; the second dorsal fin is slightly larger and originates over the rear of the anal fin base. The pelvic and anal fins are long and low, and larger than the dorsal fins. The free rear tips of the pelvic fins may be fused together to some degree, but never completely. Males have slender, pointed claspers. There are no club-shaped papillae on the distal tip of the clasper.
Biology and Reproduction: There is a moderate vertebral count, 124 total vertebrae in the holotype, 123 total in paratype, and the mean is 117.8. They are more than likely oviparous.
Behavioral Traits, Sensing and Intelligence: Juveniles occur in deeper water than adults do. They are more than likely active in nature.
Honeycomb Izak or Natal Izak Future and Conservation: They are currently considered endangered and haven’t been seen for years.
Honeycomb Izak or Natal Izak Recorded Attacks on Humans: They are not a threat to humans.